Caloric restriction (CR) is a technique in which subjects, such as mice or humans, are fed a diet which has less than a “normal” amount of food for at least a certain period of time. Typically, the amount of food given in the diet is less than 40% of the minimum recommended daily amount measured in calories. The effects of a CR diet have been extensively studied, and numerous researchers have developed techniques to screen interventions, such as therapeutic substances or compounds, which when administered to a subject on a normal diet tend to cause the subject's physiological or biological state to mimic the state of an organism on a CR diet. Such interventions are referred to as CR mimetics because they cause the biological state of the organism receiving the intervention to mimic the state of a similar organism on a CR diet even if the organism is not on a CR diet. The effects of CR diets and techniques for screening for CR mimetics are described in the following patents and published applications which are hereby incorporated herein by reference: U.S. Pat. Nos. 6,406,853 and 6,569,624 and U.S. published applications 2005/0266438, 2005/0013776, 2004/0191775, 2004/0180003, 2003/0224360 and 2003/0124540.
Another area of biological research has involved the measuring of metabolites and/or biological states of a subject and monitoring those metabolites and states. The purpose of performing the measuring or monitoring is to predict or diagnose a disease or condition of the subject. This measuring may include measuring RNA, protein or metabolite abundances or activities in cells. Examples of such measuring or monitoring are described in the patent literature, including the following patents and published applications which are hereby incorporated herein by reference: U.S. Pat. No. 6,558,955 and U.S. published applications 2005/0181354 and 2004/0047896.